Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
DTC Descriptor
DTC P0455: Evaporative Emission (EVAP) System Large LeakCircuit/System Description
The control module tests the evaporative emission (EVAP) system for a large leak. The control module monitors the fuel tank pressure (FTP) sensor signal to determine the EVAP system vacuum level. When the conditions for running are met, the control module commands the EVAP canister purge solenoid valve OPEN and the EVAP vent solenoid valve CLOSED . This allows engine vacuum to enter the EVAP system. At a calibrated time, or vacuum level, the control module commands the EVAP canister purge solenoid valve closed, sealing the system, and monitors the FTP sensor input in order to determine the EVAP system vacuum level. This turbocharged engine is equipped with a one-way flow check valve that prevents boost pressure from entering the purge line and EVAP system. The following table illustrates the relationship between the ON and OFF states, and the OPEN or CLOSED states of the EVAP canister purge and vent solenoid valves.
Control Module Command | EVAP Canister Purge Solenoid Valve | EVAP Canister Vent Solenoid Valve |
|---|---|---|
ON | Open | Closed/Not Venting |
OFF | Closed | Open/Venting |
Conditions for Running the DTC
| • | DTCs P0100, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0117, P0118, P0122, P0123, P0125, P0443, P0446, P0449, P0496, P0452, P0453, P0502, P0560, P0562, P0563, P0601, P0602, P0606, P0641, P2122, P2123, P2127, P2128 are not set. |
| • | The ignition voltage is between 11-18 volts. |
| • | The barometric pressure (BARO) is more than 68 kPa. |
| • | The fuel level is between 15-85 percent. |
| • | The intake air temperature (IAT) is between 2-32°C (35.6-90°F). |
| • | The start-up ECT and IAT are within 9°C (16.2°F) of each other. |
| • | The vehicle speed sensor (VSS) is less than 1.7 km/h (2 mph). |
| • | The engine is idling. |
| • | DTC P0455 will attempt to run up to 10 times until it successfully completes. |
| • | DTC P0455 completes one test per cold start within 10 minutes of start-up. |
Conditions for Setting the DTC
The EVAP system is not able to achieve or maintain vacuum for up to 4 times during the diagnostic test.
Action Taken When the DTC Sets
DTC P0455 is a Type B DTC.
Conditions for Clearing the MIL/DTC
DTC P0455 is a Type B DTC.
Diagnostic Aids
| • | A loose, missing, incorrect, or damaged fuel fill cap may cause this DTC to set. |
| • | To help locate intermittent leaks, use the J 41413-200 Evaporative Emission System Tester (EEST) to introduce smoke into the EVAP system. Move all EVAP components while observing smoke with the J 41413-SPT High Intensity White Light . Introducing smoke in 15-second intervals will allow less pressure into the EVAP system. When the system is less pressurized, the smoke will sometimes escape in a more condensed manner. |
| • | To improve the visibility of the smoke exiting the EVAP system, observe the suspected leak area from different angles with the J 41413-SPT . |
| • | Reviewing the Failure Records vehicle mileage since the diagnostic test last failed may help determine how often the condition that caused the DTC to be set occurs. This may assist in diagnosing the condition. |
| • | A condition may exist where a leak in the EVAP system only exists under a vacuum condition. By using the scan tool Purge/Seal function to create a vacuum, seal the system and observe the FTP parameter for the vacuum decay, this type of leak may be detected. |
| • | If a small leak is difficult to find, it may be necessary to remove the EVAP components and leak test them one at a time. |
| • | The turbocharged engine is equipped with a one-way flow check valve that will prevent boost pressure from entering the purge line and the EVAP system. This check valve will also prevent flow from the J 41413-200 from the purge valve into the EVAP system. |
Reference Information
Schematic Reference
Connector End View Reference
Electrical Information Reference
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Special Tools Required
| • | GE-41415-50 Fuel Tank Cap Adapter |
| • | J 41413-200 Evaporative Emission System Tester (EEST) |
| • | J 41413-SPT High Intensity White Light |
Circuit/System Testing
Important:
• Larger volume fuel tanks and/or those with lower fuel levels may require several minutes for the floating indicator to stabilize. • Refer to the
J 41413-200
operation manual for detailed instructions.
- Using the GE-41415-50 , connect the J 41413-200 to the vehicle filler neck.
- Seal the system and use the flow meter on the J 41413-200 , calibrated to 0.51 mm (0.02 in) to determine that there is no leak in the EVAP system.
- Start the engine with the J 41413-200 connected to the fuel filler neck.
- Allow the engine to idle.
- Use the Purge/Seal function to seal the system with a scan tool.
- Command the EVAP canister purge solenoid valve to 20 percent.
- The vacuum/pressure gage on the J 41413-200 and the FTP parameter on the scan tool should both show vacuum.
- Verify that the vacuum increases to the abort limit on the scan tool or more than 3.2 volts, and the value is closely similar between the scan tool and the vacuum/pressure gage on the J 41413-200 .
| ⇒ | If a leak is detected, use the J 41413-200 to apply smoke to the EVAP system at the filler neck until the leak is located. |
| ⇒ | If the vacuum/pressure gage shows vacuum but the FTP parameter does not show vacuum, replace the FTP sensor. |
| ⇒ | If neither the FTP parameter nor the vacuum/pressure gage shows vacuum, repair the restriction in the purge path. |
| ⇒ | If the values are not similar or the voltage did not reach 3.2 volts, replace the FTP sensor. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for engine control module (ECM) replacement, setup, and programming |
